Yamaha XJ 750 Maxim
Yamaha XJ 750 Maxim
Air cooled, four stroke, transverse four
cylinder, DOHC, 5 valves per cylinder
Bore x Stroke
65 x 56.4 mm
4x 32mm Hitachi HSC
Battery powered inductive
86 hp 62.7 kW @ 9000 rpm
61.8 Nm @ 7500 rpm
5 Speed / shaft drive
36mm Air assisted forks,
136mm wheel travel.
Dual shocks spring preload
and rebound damping adjustable. 98mm wheel travel.
12.6 sec /
Bright Lights: A Comparison of
Honda V45 Magna vs Yamaha 750 Maxim-X
Pick your own proportion of luxury and performance
for the street.
Honda's hold on the 750 custom
market in Canada has been overpowering in recent years, and much of that success
has been won by the V45 Magna. For '85, the Magna has been given a minor face
lift; its popularity doesn't warrant extensive changes.
Yamaha, on the other hand, needed
something special to crack Honda's sales grip. In a bold move, Yamaha slipped
its most potent engine technology into the conservative Maxim styling package,
hoping that an explosive amount of horsepower would shatter the Magna's status
as reigning high-tech street cruiser. The question remians, however, whether
Yamaha has succeeded in upsetting the Magna from its throne or in simply
establishing a brand-new category of machine.
Even though these two bikes
ostensibly share the same class, they differ radically in design, performance
and style. The '85 Magna's updated cosmetics are a closer reworking of the
Harley-Davidson look. The seat has been lowered, the wheelbase stretched and a
new backrest added. The Maxim-X is a typical representative of Japanese
inline-four customs. Its wheelbase is shorter, the steering head high and the
front fork very long. In contrast with some of the more successful Harley
clones, the Maxim[-X]'s custom styling appears a
There's certainly nothing dated
about the Maxim-X's engine design. The cylinder and cylinder head are virtually
identical to the FZ750's, but are mounted on crankcases derived from the
air-cooled XJ900. The advantages of a five-valve cylinder head design have been
extolled in Cycle Canada in the April and June issues. To recap them, the five
valves allow the included valve angle to be narrowed while maintaining
sufficient intake area for high rpm breathing without the need for radical
camshafts. The low valve angle permits a high compression ratio without the
onset of detonation. The theoretical results of this design are a wide powerband
and a high peak power output.
Except for the changes required
by the Maxim[-X]'s [nearly]
upright cylinder block, the FZ and Maxim[-X]
powerplants are the same. Both use 33mm constant velocity carburetors, the Maxim[-X]'s
being the sidedraft variety while the FZ's are downdraft. The three 21mm intake
and two 23mm exhaust valves are the same on both engines, as are the included
valve angles. The resulting shallow combustion chamber allows a high compression
ratio of 11.2:1 without requiring the use of premium gas. The camshaft specs
also remain identical, with 276 degrees of intake and exhaust duration, and lift
of 7.6mm and 7.4mm for the intake and exhaust valves, respectively.
The bottom end of the Maxim-X's
powerplant is based on the XJ900's crankcase, with the necessary changes to
incorporate liquid cooling. The cylinders a canted forward 14 degrees rather
than the 45 degrees of the FZ750, requiring a new lower cylinder head tier to
accommodate horizontal intake ports and sidedraft carburetors. The different
exhaust system and induction system with its curved ports result in a lower peak
power of 90hp at 9000rpm compared with the FZ's peak of 102hp.
The Honda's 90-degree V4
powerplant, first introduced in '82, has become the cornerstone of Honda's
street bike line. Although three years is a long time for a motorcycle engine to
remain unchanged in these days of rapid technical advances, a quick review of
the V45's engine specs reveals a thoroughly modern powerplant. The bore and
stroke are an extremely oversquare 70.0mm x 48.6mm, allowing the large paired
26mm intake and twin 23mm exhaust valves. Liquid cooling and the low included
valve angle of 38 degrees permit the high compression ratio of 10.5:1 without
the onset of detonation, and 32mm constant velocity carburetors complete the
[Maxim-X and Magna] engines are as different in character as they are in
design. The V45's mile-wide powerband has endeared it to thousands of riders,
sporting and cruiser enthusiasts alike. Good power starts at 2000rpm and
continues all the way to the 9800rpm redline and beyond. There is no discernible
step in the powerband, just a linear progression in power as the revs increase.
The smooth powerband and the lack of vibration at any engine speed give the
Magna an impression of relaxed competence.
A rider error at the drag strip
resulted in a burnt clutch on the V45, and we weren't able to record a
representative quarter mile time. However, the Magna delivers more than enough
power for its intended purpose. Acceleration around town is authoritative, and
passing power is readily available if the rider down-shifts to fifth gear.
Overdrive has the engine spinning at such low revs that there is simply not
enough torque to provide quick passing.
The carburetion on our Honda was
a little rough when we picked it up and it stalled repeatedly at stop lights. A
quick trip to a local Honda dealer corrected the problem. Our only major
complaint about the V45 engine also concerns the induction system. A
disconcerting amount of noise emanates from the intake tract whenever the
throttle is opened, enough to bother even those riders who wear ear plugs when
riding on the highway. The drone was worse when the engine was given lots of
throttle at low revs under heavy load. It's the loudest intake roar we've heard
from a modern Japanese motorcycle, and all of our riders found it annoying.
The Maxim-X's powerplant feels as
nervous as the Magna's is relaxed, like a frisky quarter horse chomping at the
bit compared with a constrained pacer. The exhaust note is raspy and uneven at
low revs, reminiscent of a drag machine waiting to take off from the line. As
the revs increase, it develops into a throaty roar that encourages the rider to
keep on the gas.
The exhaust note's impression of
power is not an illusion. The Maxim-X is one of the hardest accelerating 750s
we've ever ridden. It's quarter mile time of 11.66 seconds and terminal speed of
186.9 km/h (116.1 mph) are just a heartbeat behind
the FZ's 11.499 seconds at 191.4 km/h (118.9 mph).
Considering that the Maxim[-X] uses a less
efficient shaft final drive, these numbers are very impressive. The Maxim-X is
quicker than any 750 sportbike except the Suzuki GSX-R750 and the
[Yamaha] FZ750. Comparison of the intake tracts of
the Magna and Maxim-X reveals the source of the Maxim[-X]'s
superior power output. The Maxim-X's effective intake area is more than 20
percent greater than the Magna's.
However, the Yamaha's power
delivery may not appeal to everyone. The powerband starts just past 6000rpm and
continues well past the 10000rpm redline, but below 6000rpm the Maxim[-X]
feels lethargic compared with the V45 Magna. Since the top-end components are
the same as the FZ750's, which produces good torque as low as 4000rpm, we must
conclude that the Maxim[-X]'s intake and exhaust
systems are less efficient. The 33mm carburetors may be too large for the
engine, which feels over-carbureted at low speeds, similar to a hot-rodded
engine fitted with large-diameter smoothbores. The engine surged noticeably when
we first rode it, and though two subsequent tune-ups eliminated the surging, the
low-end torque didn't improve.
The impression of nervousness is
increased by the Yamaha's short gearing. Fifth gear keeps the engine revving at
little past 5000rpm at 100 km/h (62.1 mph), and a
Maxim[-X] rider often searches for a sixth gear.
The Yamaha's five-speed transmission performed flawlessly. We didn't miss any
shifts and gear changing is smooth and precise. The cable-operated clutch stood
up to the abuse of our drag strip session and gave more feedback than the
Honda's hydraulically actuated clutch.
The Magna's overdrive reduced the
engine speed for highway riding and allowed more relaxed cruising. Down-shifting
to pass was a minor penalty to pay for the benefits of the overdrive gear. There
were no major complaints with the Honda's transmission. Occasional missed shifts
can be avoided by more careful gear selection. The Honda's hydraulically
actuated clutch has a narrower engagement point than the Maxim[-X]'s.
The Maxim-X's chassis
specifications of 31.5 degrees of rake, 120mm trail and a 1520mm wheelbase
should dictate a slow-steering motorcycle. At low speeds this is indeed the
case, and the bike tends to fall into corners. But at more elevated speeds the
Maxim[-X] feels decidedly short-coupled, with the
immediate steering response of a much smaller bike. At the beginning of our test
the Yamaha was stable at high speeds, though a bit twitchy. As the rear tire
became worn, the Maxim[-X]'s stability decreased to
the point where it would occasionally wobble as speeds approached 160 km/h
(~100 mph). That was particularly noticeable after
the drag strip session, when the rear tire was near its legal wear limit.
Despite these deficiences, the
Yamaha was the preferred bike for fast cornering. The quicker steering and
shorter wheelbase make cornering transitions easier, and the Yamaha's suspension
is firmer, inspiring more confidence when well heeled over.
The Maxim-X's fork has sturdier
38mm fork tubes this year and is air-adjustable. The larger stanchions are a
welcome change since the steering head is higher than on previous Maxims,
resulting in a longer fork. With the increased power and weight of the Maxim-X,
last year's 36mm fork tubes would surely have been overworked. The fork's spring
rates are on the soft side, but stiffer than the plush Honda's, providing more
control at the expense of compliance.
The Yamaha's twin rear shocks
adjust for spring preload but not for compression or rebound damping. Adjusting
the preload can be awkWard, since the collars are close to the ends of the
upswept mufflers. The shocks are firm, providing adequate wheel control for
cornering, but they do bottom out over large bumps because of the short travel.
The new disc-type cast rear wheel may enhance the Maxim[-X]'s
looks, but it's heavier than last year's version and adds to the already
considerable unsprung weight of the shaft drive. The increased unsprung weight
taxes the limited travel of the rear shocks even further.
The Magna's steering strongly
parallels its engine performance: relaxed and confidence inspiring. The wheelbas
is a long 1565mm, rake 30 degrees and trail 106mm. The 701mm seat height lowers
the centre of gravity and contributes to the Magna's good straight-line
stability. Even with a handlebar windshield the Magna was more stable at high
speeds than the bare Maxim-X.
The Magna's suspension is even
softer than the Maxim-X's. It provides the Magna rider with a plush ride,
particularly around town, but does limit the Honda in other areas. The rear
shocks bottom easily while carrying a passenger because of the soft springs and
limited travel. Also, the softer springing causes the Magna to squirm if it's
pushed hard through corners. Even though cruiser riders aren't known for
aggressive cornering habits, most owners would benefit from stiffer spring
rates. The mushy suspension is a shame, since the Magna steers more neutrally
than the Maxim[-X] and falls into corners less.
Stiffer suspension would allow the Magna to corner better without drastically
The soft front forks of both
bikes result in a significant amount of dive under heavy braking. The Yamaha's
dual front disc brakes provide more stopping power than the Magna's, though
they're both limited by front tire traction. Both bikes have a large amount of
rake and long forks, reducing the weight on the front wheel and limiting the
front brakes' usefulness. This places more importance on the rear brakes. Most
riders find the Maxim[-X]'s rear brake more
progressive and easier to modulate than the Magna's, but the Maxim[-X]'s
rear wheel locks easily during down-shifts. The Magna's front brake is spongy
feeling compared with the Maxim[-X]'s.
The ergonomics of these two bikes
differ as much as their engine and chssis performance. The Magna is more typical
of recent Japanese cruisers; the footpegs are kicked way out front, the
handlebar swoops back to meet the rider's hands and the stepped seat is
extremely low to the ground. The Maxim-X takes a more conservative approach. Its
handlebar resembles a low rise sportbike bar but is mounted on a riser to
achieve the desired height. The footpegs are not set as far forward as the
As soon as we picked up the bikes
we mounted a clear, handlebar-mount fairing to the Magna, while the Maxim-X was
left bare. As a result the Magna was more comfortable than the Maxim[-X]
for highway use. Its radical riding position was not a hindrance because the
fairing deflected the wind blast. The Magna's seat provided more support for the
rider, mainly because of its greater width. Equipped with the handlebar-mount
windscreen the Magna made a reasonably comfortable mount for medium-length trips
on the highway.
When the fairing was removed from
the Magna the tables were turned. The Maxim[-X]'s
riding position makes much more sense at highway speeds. Riding long distance at
high speeds on the Magna is a sure way to build strong arms.
Both bikes are better suited for
urban riding. The Magna's superior seat coddles the rider, but the extreme
forward placement of the footpegs is awkWard. The Maxim[-X]'s
riding position makes more sense even in town and lets the rider feel more
comfortable balancing the bike while at a stoplight. The Magna's passenger
seating is far better than the Maxim[-X]'s. The
longer wheelbase allows more room and its backrest provides good support for the
instruments are similar to those of the V-Max, with white faces for the
tachometer and speedo. They are easier to read at night than the Honda's red
markings. Both bikes have a low fuel warning light, but only the Maxim[-X]
has a fuel petcock with a reserve position. When the Magna's light goes on,
there is 3.5L (0.77 Imp. Gal., 0.93 U.S. Gal.) of
gas remaining in the tank.
The Magna garnered marks for its
superior headlight, while the Yamaha's high beam lacked enough penetration to be
useful for highway speeds at night. Both bikes' turn lamps double as driving
lights, but only the Yamaha's turn signals are self-cancelling. A switch
actuated by the sidestand kills the Yamaha's engine should the rider try to
engage first gear while the stand is down. The Honda has no switch or warning
light, just the usual piece of rubber on the end of the stand designed to touch
the road first and push the sidestand up.
It's hard to imagine two more
different motorcycles competing in the same class. The Maxim[-X]
may be dressed in a cruiser's clothes but its engine screams sportbike. It seems
to us that the engine would be more at home in an updated version of the XJ750's
chassis. Still, the Maxim-X is the sportiest 750 cruiser you can buy.
Our initial impression of the
Magna was that it paled in comparison with the sportier Maxim[-X].
Yet, its relaxed performance slowly gained the respect of our testers. The Magna
performed every task demanded of it and can only be considered slow next to the
very quick Maxim-X. The Magna's power output and handling capabilities will keep
most cruiser riders happy.
We preferred the Maxim-X for its
sporting performance and handling capabilities. Even though these motorcycles
appear to be in head-to-head competition for the same market, they appeal to
distinctly different riders. The Maxim-X suits the rider who wants sporting
performance but absolutely has to have it in a custom package, while the Magna
appeals to the mainstream cruiser buyer, for whom ferocious acceleration and
cornering ability are secondary to styling and relaxed performance.
Cycle Canada Magazine, September 1985